5 Attributes of Decomposition

5 Attributes of Decomposition

Work Breakdown Structure (WBS)

WBS is the deliverable-oriented hierarchical decomposition of work to be executed by the project team, to accomplish the project objectives and create the required deliverables.

The WBS organises and defines the total scope of the project. The WBS subdivides the project work into smaller, more manageable pieces of work, with each descending level of the WBS representing an increasingly detailed definition of the project work.

The planned work contained within the lowest level WBS components, which are called work packages, can be scheduled, cost estimated, monitored and controlled.

The WBS represents the work specified in the current approved project scope statement. Components comprising the WBS assist the stakeholders in viewing the deliverables of the project.

Decomposition is the most effective tool for creating a WBS. It is the subdivision of the project deliverables into smaller, more manageable components until the work and deliverables are defined to work package level. The work package level is the lowest level in the WBS, and is the point at which cost and the schedule of the work can be reliably estimated.

Decomposition may not be possible for a deliverable or sub project that will be accomplished far into the future. The project management team usually waits until the deliverable or the sub project is clarified so the details of the WBS can be developed. This technique is sometimes referred to as rolling wave planning. Decomposition of the total project work generally involves the following activities:

(a) Identifying the deliverable and related work

(b) Structuring and organizing the WBS

(C) Decomposing the upper WBS level into lower level detailed components

(d) Developing and assigning identification codes to the WBS components

(e) Verifying that the degree of decomposition of the work is necessary and sufficient